By comparing two ways of learning foreign language vocabulary, the psychologists running the study showed that some strategic sleep can bring about dramatic results.

Specifically, the researchers split 40 participants into two groups and asked each group to learn some vocab words with the following technique:

Do one study session until you know all the words

Take a 12-hour break

Do another study session

The only difference between the two groups was that one did the first session in the morning and the second in the evening while the other did the first session in the evening, slept, then did the second session in the morning.

Oh, actually, there was one other difference: the group that slept ended up learning the vocab a lot more quickly. In fact, sleeping was enough to cut the amount of practice necessary in half.

The sleepers didn’t just learn vocabulary faster. When they were tested a week later and then half a year later, it turned out they also remembered a lot more of the words.

There are a couple takeaways from the study that shouldn’t be too hard to get behind if you like sleeping. The first, of course, is that if you’re trying to learn something like a foreign language, it can’t hurt to give the study-sleep-study technique a shot.

The second is that hey, everyone who says sleeping is a waste of time, take that! It turns out that sleep can actually save time.

The bad news is that after reading through this study, I don’t think I can use it as an excuse for all those times I fell asleep in class. Apparently you’re supposed to do the sleeping after you study, although I guess there’s an argument to be made that it’s extra-efficient to do them at the same time…